Never happening. Why risk $200-300m capital when you can continue selling skin gambling infrastructure to teens for $2-3 billion a year?
From a business standpoint it's a terrible idea.
Don't be ridiculous. While Valve have undoubtedly changed their business model with the success of skins and loot crates, they still are a game developer, and do develop games. HL:Alyx was announced/released very suddenly out of no where with almost no hype (or rather, it was announced so close to release that there was little time for hype), and it's actively developing Deadlock, so they
do still develop games, just very selectively now, and they are clearly quite protective over HL, and want each instalment to be memorable with significant technological advancements. It's just a matter of what advancements.
And the success of singleplayer games like Wukong, Elden Ring, etc. just prove how good, singleplayer games are still much sought after by gamers.
The meer fact that Valve
have such a lucrative "side business" if you will in skins, effectively granting them unlimited budget, and the fact that they are still privately owned, plus HL being highly lauded and highly anticipated mean it's much
more likely, surely? It's just a matter of when.